Răspuns:
4. 20 cm
2. Am aratat
3.18 garsoniere
18 apartamente cu doua camere
Explicație pas cu pas:
4. [tex]L_{m} =\frac{B+b}{2}[/tex]
⇒ [tex]B+b = 10 *2 = 20 cm[/tex]
2. [tex]a-\frac{1}{a} = \frac{3}{2}[/tex]
⇒[tex](a-\frac{1}{a})^{2} = (\frac{3}{2} )^{2}[/tex]
[tex]a^{2} - 2*a*\frac{1}{a} + \frac{1}{a^{2} } = \frac{9}{4}[/tex]
[tex]a^{2} -2 + \frac{1}{a^{2} } = \frac{9}{4}[/tex]
[tex]a^{2} + \frac{1}{a^{2} } = \frac{9}{4} + 2[/tex]
[tex]a^{2} + \frac{1}{a^{2} } = \frac{9}{4} + \frac{8}{4}[/tex]
[tex]a^{2} +\frac{1}{a^{2} } = \frac{17}{4}[/tex]
3. garsoniere - x
apartamente cu 2 camere - y
x + 2y = 54
x + y = 36/ ·2
2x + 2y = 72
........................
72 - 54 = 2x-x + 2y-2y
18 = x
⇒ 18 garsoniere
⇒ 18 apartamente cu 2 camere
Verificare : 18 · 1 camera + 18 · 2 camere = 54 camere
18+ 36 = 54
54= 54
